'84 w123 300d performance basics
 

I've had my 300d for about 2 weeks now. The PO had it setup to run wvo. When I first drove the car I thought to myself ,"damn! I know the MB diesels are slow but WTF!" Well the price was right and figured the low performance would be resolved with basic maintenance and tuning so I drove it home.

I drove It for about about a week and it ***** the bed. No start, acting like there was no fuel. After a little poking around (and talking to some old timer MB techs I know) I decided it was clogged fuel Everything! I removed the wvo components and rebuilt the injectors. Now everything is pretty well peachy. Enough bottom end that i'm not AS scared to make a left turn.

So what now? I am thinking to add boost and pyro gauges. Where are the best places to tap in for either? any gauge recommendations? Next up I want to do the basic IP mods, full load limiter removal, alda removal. Any other suggestions while im in there? Next up I want to turn up the boost. What is the highest # while still keeping in safe limits of over boost or extra high temp?

Any other suggestions or tips are appreciated! I'm super stoked on my new ride! Here in LA everyone wants to save the environment in their prius's... I want to blow black smoke in their windshields! lol! And get better mileage while Im at it!

The most common place is the underside where the wires will stay cool, but there is no reason it can't be put up top as in the attached picture.

12psi is all you need stock, 18 with the rack limiter removed. 1400*f is the egt limit.

You can go higher than 1400 but its a nice number.

I use this one... http://www.glowshiftdirect.com/3in1-Combination-Gauge-Boost-and-Exhaust-Temperature-and-Temperature-Gauge.aspx

Make sure your Banjo bolt/lines are connected and totally cleaned out. This can make a huge difference if your alda is still installed. Have you done a valve job? Also there is a great pictorial on EGT sensor install somewhere. I used that and a little common sense and it came out great...

Hmmn, I've always read 1250* F was the safe limit for aluminum pistons - since the aluminum alloy most pistons are made of starts to melt at around 1300* F.

Are the MB pistons made with some kind of coating or a special alloy that allows them to handle a couple of hundred degrees more heat without turning to slag?

Thats the key. Straight aluminum melts at 1220*f, buy making an alloy can greatly affect that.

The only real way to know its melting point for sure is to get a piston and put it in a kiln.

I adjusted my alda last night. Turned it 3/4ccw 1/4 at a time. I have been searching and could not find a walk through for this adjustment, I just followed the bits and pieces that i found in various threads.

Could someone give me a step by step for this adjustment? My main concern is that I do not know where it was before I started adjusting. The factory cap was still intact so I ASSUME that it is set to the factory spec.

After The adjustment it seemed to have a hair more power and shifted a bit smoother. But that only lasted for a few miles of driving. It then turn back to rough shifts and started to slip pretty bad in 1st gear. If I set the gear selector to L and shift manually the slipping goes away.

I have already checked all the vaccum lines and they are all holding and routed to the correct ports. But the shifts still suck. The main thing that kills me is there is no kickdown. I know there is a linkage adjustment for the tranny but I have not been able to find that procedure either.

I am going to check the fluid level tonight and see if that helps the slipping. Any other ideas???

Are there step by step pictorials for these two items?

Yes. Pulling the ALDA off is easy enough you just need big wrenches. Rack limiter removal is fairly simple. While you have the back off adjust torque to!

Thanks. I am glad to hear that it is simple, but is there a known step by step with pictures available?

So here is the ALDA.
Pic courtesy of Diesel Giant.

I have not found a write up describing removal and benefit of such. DG suggests not messing with it.

Note: The ALDA is the Square/circle looking unit above the hand. The clear hose goes to the switch over valve.
http://www.dieselgiant.com/ALDAcleaning44.JPG


If anyone has clear info with pics of the ALDA removal and load limiter removal, love to see it.

Here ya go...for the rack removal.

http://superturbodiesel.com/std/ip-full-load-adjustment-procedure-for-mw-pumps-t-189.html

As far as the ALDA, you must use a 1-1/16" and a 24mm wrench. The ALDA has a stationary thread and the pump has a compression style fitting that remains on the pump.

Fit your wrenches in a way that you can turn either one in a manner to break the ALDA loose. One you break it loose, remove the 24mm and unscrew the ALDA. After you remove it, hold it in your hand and raise it above your head, stand above a trash can and release.